Surgical Treatment after Radiotherapy for Solitary Plasmacytoma of the Cervical Spine: A Case Report

Solitary plasmacytoma is a hematologic malignancy in which about 50% of cases progress to multiple myeloma within 10 years. Local radiation therapy is effective for solitary plasmacytoma treatment, but there are cases of spinal cord paralysis due to osteolytic pathological fractures in the spine. Here, we report a 63-year-old male with spinal cord injury caused by pathologic fracture progression after radiotherapy. A 63-year-old male presented with neck pain and left hemiplegia. Imaging studies revealed a pathological fracture of the C5 vertebral body, and biopsy confirmed the diagnosis of solitary plasmacytoma. Radiation therapy temporarily improved symptoms, but progressive quadriplegia developed 2 months later. Cervical spinal cord compression due to an additional vertebral bone fracture was confirmed. Aggressive lesionectomy and fixation using simultaneous anterior and posterior combined approaches were performed. Postoperatively, paralysis completely recovered. No local recurrence or transition to multiple myeloma was observed even after 7 years of follow-up at age 70. Surgical treatment may be effective for spinal cord injury associated with pathologic fracture progression after radiotherapy for solitary plasmacytoma.